1. Technical Field
The invention is directed to image processors, particularly an image processor capable of generating a blended image from a number of image layers using alpha-blending.
2. Related Art
Information devices may employ graphical schemes. An information and system may displays maps overlaid with route information and image elements. Some systems may employ graphics display controllers that are used to control image layers that may be addressed by a computer. The image layers may be blended into an output image. The layer concept may independently control different image elements that make up a complex image.
Chroma-keying is an image blending technique. In this technique, a specific color of an image may be replaced by another (background) image. α-blending is another image blending technique. In this technique, image elements may be transparently overlaid on a background image. A color value of a blended image may then be calculated from respective color values of the image layers.
In some α-blending systems, a large amount of data needs to be generated. The data is processed to update the α-layer each time the transparency of an element changes. Some information systems lack the computing power needed to continuously update the α-layer.
Therefore, a need exists for an improved system that creates an efficient dynamic transparency effect.